JPH042999A - Radioactive ray image conversion panel - Google Patents

Abstract

PURPOSE:To prevent conspicuously a fault based on a charged phenomenon occurring on a surface on the side of a stimulated phosphor layer and to improve an antistatic performance, by a method wherein at least a part of a conversion panel is made to contain an electroconductive zinc oxide whisker. CONSTITUTION:A conversion panel is constructed of a substrate 11, a stimulated phosphor layer 12 and a protective film 13 in this order, for instance, and an electroconductive zinc oxide whisker is contained in the stimulated phosphor layer 12. The zinc oxide (ZnO) whisker used herein is shaped in a fiber or a tetrapod and has bulk specific gravity of 0.3 or below, a fiber length of 3 to 150mum, a fiber thickness of 0.3 to 3mum and a volumetric intrinsic resistance value (OMEGAcm) of 5 to 10. By this construction, occurrence of various faults due to a charged state of both surfaces of the panel and, in particular, the surface on the reading side (the side of the stimulated phosphor layer) is prevented. In repeated employment of the panel comprising carriage and lamination in a record reproducing device for information of a radiation image, in other words, improvement in a carriage characteristic, prevention of sticking of dust on the surface of the panel and improvement in the quality of a picture are enabled.

Description

[Detailed description of the invention]

[Field of the Invention] The present invention relates to a radiation image conversion panel used in a radiation image conversion method using a stimulable phosphor. “Technical Background of the Invention” As an alternative method to conventional radiography, for example, as described in Japanese Patent Application Laid-Open No. 55-12145,
A radiation image conversion method using a stimulable phosphor is known. This method uses a radiation image conversion panel (stimulable phosphor sheet) containing a photostimulable phosphor, and uses the radiation that has passed through the subject or the radiation emitted from the subject to be converted into a stimulable phosphor. The stimulable phosphor is absorbed by the phosphor, and then exposed to electromagnetic waves (excitation light) such as visible light and infrared rays.
By time-series excitation with
This fluorescence is read photoelectrically to obtain an electrical signal, and then the electrical signal is transferred to a recording material such as a photosensitive film, C
The image is reproduced as a visible image on a display device 1 such as an RT. This radiation image conversion method has the advantage that it is possible to obtain three types of informational images with a much lower exposure dose than when conventional radiography is used. Therefore, this method has a very high utility value especially in direct medical radiography such as X-ray photography for the purpose of medical diagnosis. The radiation image conversion panel used in the radiation image conversion method is
The basic structure is a support and Keijin+J provided on one side of it.
1 phosphor layer. In addition, a transparent protective film is generally provided on the surface of this stimulable phosphor layer opposite to the support (the surface that is not attached to the support).
Protects the phosphor layer from chemical deterioration or physical impact. The stimulable P phosphor layer generally consists of a stimulable phosphor and a binder that supports the stimulable phosphor in a dispersed state, or a vapor deposited or sintered layer of the stimulable phosphor. This stimulable phosphor has the property of emitting light (stimulated luminescence) when irradiated with electromagnetic waves (excitation light) such as visible light or infrared rays after absorbing radiation such as X-rays. . Therefore, the radiation transmitted through the subject or emitted from the subject is absorbed by the photostimulated +1 phosphor layer of the radiation image conversion panel in proportion to the amount of radiation, and the radiation image conversion panel is exposed to the subject or subject. It is formed as a radiation image or an accumulation image of radiation energy. This accumulated image can be emitted as stimulated luminescence light by time-series excitation with excitation light, and by photoelectrically reading this stimulated luminescence light and converting it into an electrical signal, the accumulated image of radiation energy can be generated. It becomes Noh by converting it into an image. The radiation image conversion method is a very advantageous image forming method as mentioned above, and the radiation image conversion panel used in this method is similar to the intensifying screen used in conventional radiography.
i: P color and image quality (sharpness, graininess, etc.)
It is desirable that the image be able to provide an excellent image. When carrying out the radiation image conversion method, the radiation image conversion panel usually undergoes radiation irradiation (recording the radiation image), excitation light irradiation (reading the recorded radiation image), and erasing light irradiation (
It is used repeatedly in a cycle of erasing the remaining radiation image. In fact, in a radiographic image information recording and reproducing apparatus, panels are often conveyed while being held between conveyance means such as rollers and endless belts, and are stacked and stored every r cycles. In the use of this kind of edging consisting of conveyance and lamination,
When the radiation image storage panels are stacked or transferred from the stacked state to the transport system, the front surface of one panel (the surface of the stimulable phosphor layer or the surface of the protective film) and the back surface of the other panel (the surface of the support) Physical contact occurs, such as friction between the panels, friction between the edge of the panel and the front or back surface of another panel, and friction between the panel and conveyance means (rolls, belts, etc.). Generally, from the viewpoint of flexibility +1 required when transporting the radiation image storage panel, it is preferable to use a plastic film such as polyethylene prephthalate film or Meishin paper as the support material. However, on the other hand, due to physical contact in the conveyance system, both sides of a panel made of plastic film or paper tend to become electrically charged; generally, the front surface of the panel tends to become negatively charged, and the back surface tends to become positively charged. This charging phenomenon causes various problems in implementing the radiation image conversion method. For example, if the surface of a radiation image conversion panel is electrically charged, when the panels are transferred from a stacked state to a transport system, the front surface of the panel and the back surface of another panel may come into close contact with each other in the thickness direction of the panel (perpendicular to the surface direction). (direction), it will peel off.

[■
As a result of being sent into the conveyance system in a state of failure, it may become impossible to perform normal operations thereafter. Also, normally, reading of the panel by irradiation with excitation light is performed from the surface on the side of the stimulable phosphor layer, but the charged panel surface is covered with 11 particles of dust in the air, and 411 particles are deposited on the surface during readout. Since the excitation light is scattered by the dust, the resulting image has a significantly reduced quality. Also,
Sensitivity may drop due to the panel surface not being discharged, noise such as static marks may occur in the obtained image, resulting in image unevenness, and furthermore, discharge from the panel surface may cause damage to the person handling the panel. It may be shocking. In order to prevent the radiation image storage panel from being charged, a layer made of a conductive material and having a surface electrical resistivity of 1011 or more is coated on the surface of the support opposite to the side on which the stimulable phosphor layer is provided.
A radiation image conversion panel provided with a charging aid 11 layer having a charge resistance of Ω or less is already known (Japanese Patent Application Laid-Open No. 62-879004).
. In addition, in the same manner [1], between the support and the phosphor layer, at least one conductive substance selected from the group consisting of metal oxides, carbon black, and conductive organic substances is formed;
A radiation image storage panel provided with an antistatic layer having a surface electrical resistivity of 10<12 >[Omega] or less is already known (Japanese Patent Application Laid-Open No. 174700/1983). In addition, similar to the history [1] K 20-n is applied to at least part of the radiation image conversion panel.
A radiation image conversion panel containing a fibrous conductive material such as a single crystal fiber of TiO2 is also known (Japanese Patent Laid-Open No. 167298/1983). [Object of the Invention] The object of the invention is to provide a radiation image conversion panel with excellent antistatic performance. Another object of the present invention is to provide a radiation image conversion panel in which the occurrence of image unevenness due to discharge is prevented. Another object of the present invention is to provide a radiation image conversion panel in which image sharpness, which is likely to occur due to the presence of scratches on the static protection 1, is improved. [Structure of the Invention] The present invention provides a radiation image conversion panel comprising a support such as a plastic film or paper, and a stimulable phosphor layer provided thereon. At least partially conductive oxide II! A radiation image conversion panel containing lead whiskers is provided. The zinc oxide (zno) whiskers used in the present invention have a fibrous or tetrabot-like shape, and usually have a bulk specific gravity of 0°3 or less, a fiber length of 3 to 150 μm, and a lfi fiber thickness of 0.3. ~3 μm and a volume resistivity value (0 cm) of 5 to 10. First, the invention of the tree was made by containing conductive zinc oxide whiskers in at least a portion of the radiation image storage panel, thereby eliminating the hindrance caused by charging on both surfaces of the panel, especially the readout side (stimulable phosphor layer side) surface. This is to realize prevention 11-1. That is, in the repeated use of a panel consisting of transportation and lamination within a radiographic image information recording/reproducing apparatus, it is possible to improve the transportation characteristics, prevent dust from adhering to the panel surface, and improve image quality. In particular, conductive zinc oxide whiskers may be present in at least one layer of a multilayer panel, such as a protective layer (e.g., friction reducing layer), a subbing layer, a light reflective layer, a stimulable phosphor layer, an adhesive layer, etc. 1. By setting the surface electrical resistivity to 10 12 Ω or more, charging on the surface of the panel can be significantly prevented. In the present invention, the surface electrical resistivity refers to a value measured under the conditions of a temperature of 23° C. and a humidity of 53% RH. According to the radiation image storage panel of the present invention, the electrically conductive zinc oxide whiskers in the panel can significantly prevent problems caused by charging phenomena occurring on the surface of the stimulable phosphor layer. This is because the lines of electric force that had been extending outward from the charges gathered on the surface of the stimulable phosphor layer are directed inward of the panel (toward the back surface of the panel) by the conductive zinc oxide whiskers. (i.e. closure of electric field lines)
Therefore, it is assumed that the surface on the side of the stimulable phosphor layer is in an uncharged state. For the reason described below, in the panel of the present invention, the cleaning power due to static electricity on the stimulable phosphor layer side surface can be reduced. Normally, in a recording and reproducing device for radiographic images and information, when the panels are transferred from a stacked state to a conveyance system, they are separated one by one by being pulled up in a direction perpendicular to the surface direction of the panels using a suction cup or the like. According to the present invention, it is possible to prevent knee panels from being sent into the conveyance system simultaneously in an overlapping state during this transition process. Further, it is possible to prevent dust and the like from adhering to the surface of the panel on the stimulable phosphor layer side. Furthermore, since the discharge phenomenon on the panel surface can be significantly reduced, it is possible to prevent low sensitivity due to discharge and image unevenness due to static marks, etc., and to effectively eliminate shock to the human body. . In particular, the conductive zinc oxide whiskers of the present invention can be used as a layer between the support and the stimulable phosphor layer in a radiation image storage panel using a support filled with white pigment to improve reflectivity. It is preferable to place the In other words, in order to improve the sharpness of images obtained by radiation image conversion panels, it is known to use a support filled with white pigment to improve reflectivity. In conventional radiation image storage panels, when conductive lead oxide whiskers are arranged in a layer between the support and the stimulable phosphor layer, the same phenomenon that tends to occur when conventional conductive materials are arranged in the same way can be avoided. This has the advantage that deterioration in sharpness when compared in terms of sensitivity is effectively prevented. Next, preferred embodiments of the radiation image conversion panel of the present invention will be listed. (1) A radiation image storage panel that includes a support or a white pigment. (2) The radiation image storage panel has an undercoat layer between the support and the stimulable phosphor layer, the undercoat layer contains conductive zinc oxide whiskers, and the undercoat layer includes conductive zinc oxide whiskers. Surface electrical resistivity 1
A radiation image conversion panel having a resistance of 0.012Ω or less. (3) The radiation image storage panel has a reflective layer between the support and the stimulable phosphor layer, the reflective layer contains conductive zinc oxide whiskers, and the surface of the reflective layer has a A radiation image conversion panel having a resistivity of 1012Ω or more. (4) The radiation image conversion panel has a protective layer formed over the stimulable phosphor layer via an adhesive layer, the adhesive layer contains conductive zinc oxide whiskers, and the adhesive layer A radiation image conversion panel having a surface electrical resistivity of 1012Ω or less. (5) The radiation image conversion panel has a protective layer on the stimulable phosphor layer via an adhesive layer, the protective layer contains conductive zinc oxide whiskers, and the protective layer A radiation image conversion panel having a surface electrical resistivity of 1012Ω or less. (6) Conductive zinc oxide whiskers are contained in the stimulable phosphor layer, and the surface electrical resistivity of the stimulable phosphor layer is 1.
A radiation image conversion panel having a resistance of 0.012Ω or less. (7) A layer containing conductive zinc oxide whiskers is provided on the side opposite to the side facing the stimulable phosphor layer of the support, and the surface electrical resistivity of the layer containing conductive curved lead oxide whiskers is A radiation image conversion panel in which the resistance is 1012Ω or less. [Description of the Invention] Embodiments of the radiation image conversion panel of the present invention will be described with reference to the accompanying drawings. (1) to (5) in FIG. 1 are sectional views each showing a configuration example of the radiation image conversion panel of the present invention. In FIG. 1, the radiation image storage panel is composed of a support 11, a stimulable phosphor layer 12, and a protective film 13 in this order, and conductive zinc oxide whiskers are contained in the stimulable phosphor layer 12. In (2), an undercoat layer 14 is provided between the support 11 and the stimulable phosphor layer 12, and the conductive oxide bent whisker is contained in the undercoat layer 14. ( In 3), a light reflective layer 15 is provided between the support 11 and the stimulable phosphor layer 12, and the conductive zinc oxide whiskers are contained in the light reflective layer 15. In (4), Conductive zinc oxide whiskers are adhesive layer 1
It is contained in 6. In (5), a pack layer 17 made of conductive zinc oxide whiskers is provided on the side of the support 11 that does not face the stimulable phosphor layer. However, the configuration examples in (G) are typical embodiments of the radiation image conversion panel of the present invention, and the present invention is not limited to these embodiments. It is sufficient that the radiation image storage panel has at least a support and a stimulable phosphor layer, and the conductive zinc oxide whiskers are contained in either layer. For example, the conductive zinc oxide whiskers are contained in the support or the protective film. Alternatively, a thin layer of conductive zinc oxide whiskers may be provided on the surface of the panel facing the stimulable phosphor layer or between arbitrary layers. The radiation image storage panel of the present invention can be manufactured, for example, by the method described below. The support used in the present invention is a film of plastic material such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, polycarbonate; or a film of a plastic material such as ordinary paper, baryta paper, resin coated paper, or pigmented material such as titanium dioxide. It is a type of paper that contains picment paper, polyvinyl alcohol, etc. However, in consideration of the characteristics and handling of the radiation image storage panel as an information recording material, a particularly preferred material for the support in the present invention is a plastic film. This plastic film may be incorporated with a light-absorbing substance such as carbon black, or may contain titanium dioxide (rutile, anatase or pulchite), aluminum oxide, silicon oxide, zinc oxide, lead carbonate, or water. Lead oxide, barium sulfate, barium halide (e.g., BaF
A white pigment (light-reflecting substance) such as (:Jl, BaFBr) may be mixed in. The use of the latter light-reflecting support containing a white pigment improves the sensitivity of the radiation image storage panel. [Increasing sensitivity] Regarding the inclusion of a light-reflecting substance such as di-titanium oxide, aluminum oxide, silicon oxide, zinc oxide, etc. in a support made of a plastic film, Japanese Patent Application Laid-Open No. 72437/1984 describes There is a disclosure. The support used in the present invention is preferably a light-reflective support containing the latter white pigment. Specific examples of light reflective substances include AJQ20. l, Z
r02, T i02 , BaSO4, S 102, Z
nS, ZnO, CaCO3, Sb203, Nb2O5,
2PbCO3・Pb(OH)2, MgO1M”FX (where M” is at least one of Ba, Ca and Sr, and X is at least one of C1 and Br), Litopone (BaS04+Zn5), Ca Examples include white pigments such as acid magnesium, basic lead silicate, basic lead phosphate, and aluminum silicate; and hollow structured polymer particles (polymer pigments). The hollow polymer particles are made of, for example, a styrene polymer or a styrene/acrylic copolymer, and have an outer diameter in the range of 0.2 to 1 μm and a small pore diameter (inner diameter) of 0.05 μm.
These are fine particles in the range of ~0.7 μm. A light reflective layer can be provided on one of the supports. In particular, when a light-reflecting support filled with a white pigment is not used as the support, it is desirable to provide a light-reflecting layer filled with a white pigment on F of the support. Furthermore, Japanese Patent Laid-Open No. 12600/1983 discloses the provision of a white pigment light-reflecting layer between the support and the stimulable phosphor layer in order to increase the sensitivity of the radiation image conversion panel. (Specific examples of white pigments include titanium white, lead white, zinc sulfide, alumina, and magnesium oxide)
. The light-reflecting layer is a layer made of a binder containing and supporting a light-reflecting substance in a dispersed state. Specific examples of the light-reflective substance include the same substances as those used for filling the support described above. To form the light-reflecting layer, first, particles of the above-mentioned light-reflecting substance and a binder were added to an appropriate solvent and mixed thoroughly to prepare a coating solution in which the light-reflecting substance was uniformly dispersed in the binder solution. rear,
This can be carried out by uniformly applying this coating liquid onto the surface of the support to form a coating film, and then heating and drying it. The binder and solvent for the light-reflecting layer can be selected from those used as binders and solvents for forming a stimulable phosphor layer, which will be described later. In addition, when the light-reflecting material is hollow polymer particles,
An aqueous polymeric substance such as an acrylic acid copolymer may be used as the binder. Furthermore, the coating liquid may contain various dispersants, plasticizers, colorants, etc. used in the phosphor layer coating liquid described below. The mixing ratio of the binder and the light-reflecting substance in the coating solution is generally selected from the range of 1: to 1:50 (weight ratio),
It is preferably in the range of 1:2 to 1:20 (weight ratio). The thickness of the light reflective layer is preferably 5 to 100 μm. Conductive zinc oxide whiskers, which are a characteristic feature of the present invention, may be contained in this light-reflecting layer. In this case, conductive zinc oxide whiskers are added and mixed with a light-reflecting substance when preparing a coating solution, and the resulting coating solution is used to form a light-reflecting layer. Conductive oxide contained in a dispersed state in the light reflecting layer <π of ni lead whiskers
Although it varies depending on the location of the light-reflecting material and the layer thickness of the light-reflecting layer, it is generally in the range of 1 to 50% by weight, preferably 5 to 20% by weight, based on the light-reflecting material. in range. The light reflecting layer containing conductive zinc oxide whiskers has a resistance of 10′2Ω.
It is preferable to have a surface electrical resistivity of 41-. Here, the surface electrical resistivity is a value measured under conditions of a temperature of 23° C. and a humidity of 53% RH. An undercoat layer may be provided on the surface of the support in order to strengthen the bond between the support and the stimulable phosphor layer. As the resin for the undercoat layer, for example, polyacrylic resin,
Examples include polyester resins, polyurethane resins, polyvinyl acetate resins, and ethylene/vinyl acetate type combinations. However, the resin used for the undercoat layer is not limited to these resins, for example,
Any resin (adhesive) conventionally used in the undercoat layer
You can also use Further, the resin may be crosslinked with an aliphatic sardine, an aromatic isocyanate, a melamine, an amino resin, a derivative thereof, or the like. To form the F coating layer, add the above resin to a suitable solvent and 1-
After preparing a coating solution, the coating solution is evenly applied to the surface of the support using ordinary coating means to form a coating film, and then the coating film is gradually heated and dried. This is done by As the solvent for preparing the coating solution, the solvent used in forming the stimulable phosphor layer, which will be described later, can be used. ``The thickness of the undercoat layer is preferably 3 to 50 μm. Conductive zinc oxide whiskers, which are a characteristic feature of the present invention, may be contained in this undercoat layer, in which case:
When preparing a coating solution for an undercoat layer, conductive zinc oxide whiskers are added and mixed with the resin, and the obtained coating solution is used to coat and form an undercoat layer on a support. The amount of conductive zinc oxide whiskers contained in a dispersed state in the undercoat layer varies depending on the layer thickness of the undercoat layer, but is generally 1 to 50 times the resin.
1-%, preferably 5-20['Trψ%
within the range of The undercoat layer containing conductive zinc oxide whiskers preferably has a surface electrical resistivity of 10 12 Ω or less from the viewpoint of antistatic properties. However, if the surface resistivity is too small, the apparent friction will increase when two panels are stacked on top of each other, making it difficult to shift them in the plane direction, or the flow of charges (especially As a result, when the end of the panel comes into contact with a human body, a shock is likely to occur. Therefore, from the viewpoint of ease of separation of the panels in the direction of shear and prevention of impact caused by charge in and out, it is desirable that the surface resistivity be 10I0Ω or more. In the present invention, the conductive zinc oxide whiskers are preferably dispersed and contained in the undercoat layer or the light-reflecting layer from the viewpoint of antistatic effect and ease of production. In addition, as described in JP-A-58-200200, the sharpness of the image is improved [1. When the surface is provided with a light reflecting layer or an undercoat layer, fine irregularities may be uniformly formed on the surface (meaning the surface). Next, a stimulable phosphor layer is formed on the support (light reflective layer or undercoat layer). The stimulable phosphor layer is generally a layer made of a binder containing and supporting particles of the stimulable phosphor in a dispersed state. Stimulable phosphors are phosphors that exhibit stimulated luminescence when irradiated with radiation and then irradiated with excitation light, as mentioned above.
From a practical standpoint, it is desirable that the phosphor be a phosphor that exhibits stimulated luminescence in the wavelength range of 300 to 500 nm when excited by excitation light in the wavelength range of 400 to 900 nm. Examples of stimulable phosphors used in the radiation image storage panel of the present invention include SrS:Ce, Sm, and SrS:Eu, which are described in US Pat. No. 3,859,527. Sm, TiO2:Er, and La2O2S:Eu,
Sm. ZnS described in Japanese Patent Application Laid-Open No. 55-12142
: Cu, Pb, Ba0-xAu2o3:Eu (tatashi, 0.8≦X≦10), and M”0-xSiO2
:A (Tatashi, M" is Mg, Ca, Sr, Zn, Cd,
or Ba, where A is Ce, Tb, Eu, Tm, Pb
, TIl, Bi, or Mn, and X is 0.5≦X
B
at −x y 1M g X , Ca y ) F
X'. aEu2+ (where X is at least - of CR and Br, X and y are O<x+y≦06 and xy≠0, and a is 10-'≦a≦5X10-2
), LnO described in JP-A-55-12144
X: xA (where Ln is at least one of La, Y, Gd, and Lu, X is at least one of CX and Br, A is at least one of Ce and Tb, and , X is O<x<0.1)
, described in Japanese Patent Application Laid-Open No. 55-12145 (Ba
t-X, M2++t) FX: yA (, Tatashi,
M2+ is at least - of Mg, Ca, Sr, Zn, and Cd, X is at least - of Cfl, Br, and I, and A is Eu, Tb, ce, Tm, Dy, P
At least - of r, Ho, Nd, Yb, and Er, and X is 0≦X≦0.6, and y is 0≦y≦0
．． 2), M”FX-xA: yLn [Tatashi, M
II is at least one of Ba, Ca, Sr, Mg, Zn, and Cd; A is Bed, MgOCa, O
lS ro, Bad, ZnO, Al2O2, Y2O3,
La201, In2o, 5lo2, TiO2, ZrO2
, GeO2,5no2, Nb201, Ta205, and TiO2, Ln is Eu, Tb
, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er,
At least one of Sm and Gd, X is CR1
Br, and at least one of I, X and y are respectively 5X10"≦X≦0.5, and o<y
≦02] is described in JP-A-56-116777 (B
at-y, M”x)F2・aBaX2yEu,
zA [M'' is at least one of helium, magnesium, calcium, strontium, zinc, and cadmium, X is at least one of chlorine, bromine, and iodine, and A is at least one of zirconium and scandium. at least one type, and a, x, y, and 2 are each 0.5≦a≦125.0≦X≦1.10
-'≦y≦2X 10 paulownia, and O<z≦1゜]
Phosphor expressed by the composition formula, JP-A-57-23673
(Ba,,,M”X)F2 described in the publication No.
aBaX2: yEu, zB [M'' is at least one of helillium, magnesium, calcium, strontium, zinc, and cadmium; X is at least one of chlorine, bromine, and iodine;
a, X, y, and Z are each 0.5≦a≦1.25
, 0≦X≦1, 10-6≦y≦2×10-1, and O
<z≦2
+-8, M”X)F2 ・aBaX2 :yEu,
zA [M'' is at least one of beryllium, magnesium, calcium, strontium, zinc, and cadmium; X is at least one of chlorine, bromine, and iodine; A is at least one of arsenic and silicon; a, x, y, and Z are each 0.5≦a≦1.25.0≦X≦1.10-6≦y≦2
x10-1, and 0<z≦5X10-';
OX: xCe [However, M1'' is Pr, Nd
, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm,
is at least one kind of minivalent metal selected from the group consisting of Yb and Bi, X is one or both of CI2 and Br, and X is O<x<0
．． A phosphor represented by the composition formula of
a I −X M X/2 L, /2 F X:
y E u 2” [However, M is Li, Na, R
b, and represents at least one alkali metal selected from the group consisting of Cs; L represents Sc, Y, La, Ce;
, Pr, Nd, Pm, Sm, Gd, Tb, Dy. HOlEr, Tm, Yb, Lu, Aft, , Ga, In
, and TI; X represents at least one halogen selected from the group consisting of 6°C, Br, and summer:
A phosphor represented by the composition formula:
X −xA: yEu” [where X is CI, Br
, and (); A is a fired product of a tetrafluoroboric acid compound; and X is 10-6≦X≦0.1, and y is o<y≦ A phosphor represented by the composition formula of
X-xA: yEu” [where X is CI, Br,
and at least one halogen selected from the group consisting of I: A is selected from the group of hexafluoro compounds consisting of salts of monovalent or diovalent metals of hexafluorosilicic acid, hexafluorotitanic acid, and hexafluorozirconic acid; It is a fired product of at least one type of compound: and X is 10-6≦X≦0.1, and y is o<y≦
0.1], a phosphor represented by the composition formula, JP-A-5
BaFX-xN described in Publication No. 9-56479
aX′:aEu” [where X and X′ are each at least one of CI, Br, and ■,
X and a are respectively 0<x≦2 and O<a≦0.
A phosphor represented by the composition formula of
X −xNaX':yEu": zA [Tatashi, M"
is at least one alkaline earth metal selected from the group consisting of Ba, Sr, and Ca;
are each CI! , Br, and ■; A is ■, C;
r, Mn, Fe, COI and Ni: and X is O<x≦2, y
is o<y≦0.2, and Z is O<z≦10−2], JP-A-59-7520
MIIFX-aM'X' described in Publication No. 0
・bM'"X"cM"'X"' ・xA:
yEu" [where M" is at least one kind of alkaline earth metal selected from the group consisting of Ba, Sr, and Ca; MI is at least one kind selected from the group consisting of Li, Na, Rb, and C8 The alkali metals are: M'1 is at least one mini-valent metal selected from the group consisting of Be and Mg, and M'' is An, Ga,
At least one trivalent metal selected from the group consisting of In and I42: A is a metal oxide: X is C
is at least one halogen selected from the group consisting of a, Br, and summer;
is at least one kind of halogen selected from the group consisting of F, Cu, Br, and I; and a is O≦a≦2
, b is 0≦b≦10−, c is 0≦C≦10 and a+
C≧10-6; X is O<x≦0.5, y is o<y
≦0.2] A phosphor represented by the composition formula M”X described in JP-A-60-84381
, ・aM"
at least one halogen selected from the group consisting of JZ, Br and I), and xf-x'; and a is 0, 1≦a≦10.0, and X is O<x≦02. ] A stimulable phosphor represented by the composition formula M" described in JP-A-60-101173
FX-aM'
s is at least one alkali metal selected from the group consisting of: X is at least one halogen selected from the group consisting of CII, Br, and I;
is at least one halogen selected from the group consisting of f2, Br and I: and a and X are each 0
≦a≦4.0 and 0<x≦0.2] A stimulable phosphor represented by the composition formula M' :xBi [where, Ml is at least one kind of alkali metal selected from the group consisting of Rh and Cs; X is at least one kind of halogen selected from the group consisting of Cu, Br and ■; and X
is a numerical value in the range of O<x≦0.2] A stimulable phosphor represented by the composition formula: JP-A-61-72087 and JP-A-61-72
Examples include the alkaline earth metal halide phosphor described in Japanese Patent No. 088. In addition, the M"X2 .aM"X 2:
It may be contained in the following proportions per mole of aMIIX'. bM described in JP-A-60-166379
'X'' (However, Ml is at least one alkali metal selected from the group consisting of Rb and Cs, and
” is at least one kind of halogen selected from the group consisting of F, Cf2, Br and I, and b is o<b
si0.0): bKX”-cMgX”-dM” described in JP-A No. 60-221483
'X"" (However, Mlll is Sc, Y, La,
At least one trivalent metal selected from the group consisting of Gd and Lu; X'', X''° and X'' are all at least one halogen selected from the group consisting of F, CIl, Br and I , I'm moping, c and d are fidgety, 0≦b≦2.0.0≦C≦2.0.0≦d≦2
．． 0 and 2X10-5≦b+c+d)
:y described in Japanese Patent Application Laid-Open No. 60-228592
B (however, y is 2X10""≦y≦2X10-'); bA described in JP-A-60-228593 (however, A is at least one type selected from the group consisting of 5i02 and P2O5); There are oxides, and there are
is 10-4≦b≦2X10-'); JP-A-611
bsi described in Publication No. 20883. (b is o<b≦3X10-2); b S n described in JP-A-61-120885
X'' (where X'' is at least one kind of halogen selected from the group consisting of F, Cfl, Br and I, and b satisfies o<bsi0-3): JP-A-61-235486 bCsX″
-cSnX" (However, x" and X"' are each at least one halogen selected from the group consisting of F, (12, Br and I, and b and C are each o and 10-6≦C≦2X1
0-2) and bCsX"-yLn" (Tatashi,
x” is at least one kind of halogen selected from the group consisting of F, C11, Br and I, and Ln is 5C1Y
, Ce, PrX Nd, Sm, Gd, Tb, Dy, Ho
, Er, Tm, Yb and Lu, at least one rare earth element selected from the group consisting of b and y.
are o<b≦10.0 and 10-6≦y≦1, respectively.
．． 8X10-'). Among the above-mentioned photostimulable phosphors, Nivalent europium-activated alkaline earth metal halide phosphors and rare earth element-activated rare earth oxyhalide phosphors are particularly preferred because they exhibit high-intensity stimulated luminescence. However, the stimulable phosphor used in the present invention is not limited to the above-mentioned phosphors, but may also be any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light. Anything is fine. Examples of binders for the stimulable phosphor layer include proteins such as gelatin, polysaccharides such as Textran, or natural polymeric substances such as gum arabic, and polyhinyl butyral, polyvinyl acetate, nitro Cellulose, ethylcellulose, hnyritene chloride/vinyl chloride copolymer, polyalkyl (meth)acrylate, vinyl chloride/
Mention may be made of binders typified by synthetic polymeric materials such as vinyl acetate copolymers, polyurethanes, cellulose acetate butyrate, polyhinyl alcohol, linear polyesters, and the like. Particularly preferred among such binders are nitrocellulose, linear polyesters, polyalkyl (meth)acrylates, mixtures of nitrocellulose and linear polyesters, and mixtures of nitrocellulose and polyalkyl (meth)acrylates. be. Note that these binders may be crosslinked with a crosslinking agent. The stimulable phosphor layer can be formed on the support, for example, by the following method. First, particles of the stimulable phosphor and a binder are added to a suitable solvent and mixed for 1 minute to form a coating solution in which the phosphor particles are uniformly dispersed in the binder solution. Prepare. Examples of solvents for preparing coating solutions include lower alcohols such as methanol, ethanol, n-propanol, and n-butanol; chlorine-containing hydrocarbons such as methylene chlorite and ethylene chloride; acetone, methyl ethyl ketone, and methyl isobutyl. Ketones such as ketones; esters of lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, and butyl acetate; ethers such as dioxane, ethylene glycol monoethyl ether, and ethylene glycol methyl ether; and mixtures of 1,000 straws. be able to. The mixing ratio of the binder and the stimulable phosphor in the coating solution is generally from I:1 to 1:1.
100 (weight ratio), and especially 1
It is preferable to select from the range of :8 to 1:40 (weight ratio). The coating solution contains a dispersant to improve the dispersibility of the stimulable phosphor in the J-coating solution, and a dispersant to improve the dispersibility of the stimulable phosphor in the stimulable phosphor layer after formation. Various additives such as plasticizers may be mixed to improve the bonding strength between the materials. Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid, lipophilic surfactants, and the like. Examples of plasticizers include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalylethyl glycolate, butyl phthalyl butyl glycolate; Polyesters of polyethylene glycol and aliphatic I can do it. 1- Spread the coating solution prepared as described above evenly on the support.
A coating film is formed by applying it to the surface. This coating film 1 operation can be carried out using conventional coating film removal means such as a doctor plate, roll coater, knife coater, etc. Then, the formed coating film is gradually heated and dried to complete the formation of the stimulable phosphor layer on the support. The thickness of the stimulable phosphor layer varies depending on the characteristics of the radiation image conversion panel where l=I, the type of phosphor, the mixing ratio of the binder and the phosphor, etc., but is usually 20 μm to 1 mm. . However, the thickness of this layer is preferably 50 to 500 μm. Note that the bright phosphor layer does not necessarily need to be formed by directly applying the coating solution to the support as described in F. - After forming a phosphor layer by applying a coating solution and drying it, this is pressed onto the support, or the support and the phosphor layer may be bonded without using an adhesive. . Alternatively, as described in JP-A-63-19600, after forming a powder of stimulable phosphor particles or a dispersion containing phosphor particles and a binder into a sheet, It can also be formed by sintering this molded product and then bonding the sintered phosphor layer onto a support using an adhesive or the like. Alternatively, a vapor-deposited phosphor layer may be provided by directly vacuum-depositing a stimulable phosphor onto the support. In particular, when the phosphor layer is provided by sintering, the relative density of the phosphor layer can be made as high as 70% or more, and image quality such as sharpness can be improved. Conductive zinc oxide whiskers, which are a characteristic requirement of the present invention, may be contained in this photostimulable phosphor layer, and in that case, when preparing the coating solution for the phosphor layer, Conductive zinc oxide whiskers are added and mixed with the phosphor, and a phosphor layer is coated on the support 1- using the obtained coating film 1 liquid. The conductive zinc oxide whiskers contained in a dispersed state in the phosphor layer vary depending on the company of the stimulable phosphor and the thickness of the phosphor layer, but in general, it is
-50% by weight, preferably 5-20% by weight
within the range of The stimulable phosphor layer containing conductive zinc oxide whiskers is
It is preferable to have a surface electrical resistivity of 10 12 Ω or more. Note that, as described above, the stimulable phosphor layer does not have to be a layer dispersed in a binder, such as a deposited or sintered product of a stimulable phosphor. Since the production and characteristics of these stimulable phosphor sintered layers, stimulable phosphor vapor deposited layers, etc. are already known, detailed description will be omitted in this specification. A transparent protective film may be provided on the surface of the stimulable phosphor layer opposite to the side in contact with the support for the purpose of physically and chemically protecting the phosphor layer. The transparent protective film is made of, for example, a cellulose derivative such as cellulose acetate or nitrocellulose; or a synthetic polymer material such as polymethyl methacrylate, polyhinyl butyral, polyhinyl formal, polycarbonate, polyvinyl acetate, or vinyl chloride/vinyl acetate copolymer. It can be formed by coating the surface of a stimulable phosphor layer in the form of a solution prepared by dissolving a transparent polymeric substance such as in a suitable solvent. Alternatively, it can also be formed by adhering to the surface of a transparent thin stimulable phosphor layer separately formed from polyethylene terephthalate, polyethylene, polyvinylidene chloride, polyamide, etc. using a suitable adhesive. It is desirable that the transparent protective film J9 formed in this manner has a thickness of approximately 01 to 20 μm. The conductive zinc oxide whiskers, which are a characteristic feature of the present invention, may be contained in a layer made of an adhesive used to bond the protective film and the stimulable phosphor layer. As the adhesive, various substances commonly known as adhesives and the above-mentioned binder for the stimulable phosphor layer can be used. To form an adhesive layer and a protective film containing conductive zinc oxide whiskers, the zinc oxide whiskers are first added to an adhesive solution and thoroughly mixed to prepare a coating solution in which the whiskers are evenly dispersed. Next, the obtained coating liquid is evenly applied to the surface of a separately formed transparent thin film, and then the layer is superimposed and adhered to the surface of the stimulable phosphor layer. The content of conductive zinc oxide whiskers varies depending on the thickness of the adhesive layer, etc., but is generally 1 to 5% of the adhesive.
It is in the range of 0% by weight, preferably in the range of 5-20% by weight. Preferably, the adhesive layer containing conductive zinc oxide whiskers has a surface electrical resistivity of 10 12 ohms or less. Alternatively, the introduction of conductive zinc oxide whiskers, which is a characteristic requirement of the present invention, can be applied to a layer made of zinc oxide whiskers (antistatic layer) on the surface of the panel (support surface, protective film surface, etc.) or on any layer. This may be done by providing it between the layer and the layer. In that case, the layer consisting of conductive zinc oxide whiskers is prepared by adding zinc oxide whiskers and a binder to a suitable solvent and mixing them thoroughly to uniformly disperse the zinc oxide whiskers in the binder solution. After preparing a coating solution, the layer can be formed by coating and drying the coating solution on the surface of a desired layer such as the surface of a support. Examples of the binder include synthetic resins such as polyacrylic resins, polynisder resins, polyurethane resins, polyvinyl acetate resins, and ethylene/vinyl acetate copolymers. Particularly preferred are polyester resins and polyacrylic resins. Further, the solvent can be selected from those used as solvents for forming the stimulable phosphor layer. The content of conductive zinc oxide whiskers generally ranges from 1 to 50% by weight of the binder, preferably from 5 to 20%. The layer thickness of the layer of electrically conductive zinc oxide whiskers is generally in the range from 1 to 50 μm. Further, it is preferable that this layer has a surface electrical resistivity of 10<12 >F or less. Furthermore, if desired, damage to the radiation image conversion panel can be prevented.
- To achieve this, at least one edge (side surface) of the panel may be provided with a border. The conductive zinc oxide whiskers may be included in this border. The radiation image conversion panel of the present invention is disclosed in Japanese Patent Application Laid-Open No. 5516350.
The image may be colored with a coloring agent as described in Japanese Patent Application Laid-Open No. 57-96300, etc., and the sharpness of the image can be improved by this coloring. In addition, the radiation image conversion panel invented by Wood was published in Japanese Patent Application Laid-Open No. 55-14644.
As described in Japanese Patent No. 7, white powder may be dispersed in the stimulable phosphor layer. Next, Examples and Comparative Examples of the present invention will be described. However, each of these does not limit the invention. [Example 1] Polyester resin (Vylon 300, manufactured by Toyobo ■),
Add conductive zinc oxide whiskers (trade name: Banatetra, manufactured by Matsushita Industrial Equipment Co., Ltd.) and use a ball mill to prepare a uniformly dispersed coating solution (conductive P and whisker clearness relative to polyester solid content: 10% by weight, 9%). did. A barium sulfate-infused white polyethylene terephthalate sheet placed horizontally on a glass plate (support, Q.25
After forming a coating film by uniformly applying the above coating solution using a dofter blade, the coating film was
It was heated to 0° C. and dried to form an undercoat layer (conductive undercoat layer) with a layer thickness of about 20 μm. Next, a powdered nivalent europium-activated barium fluoride bromide phosphor (B a F B r :0.001E u
”) and a linear polyester resin, methyl ethyl ketone was added, and nitrocellulose with a degree of nitrification of 11.5% was further added to prepare a dispersion containing the stimulable phosphor in a dispersed state.Next, After adding tricresyl phosphate, n-butanol, and methyl ethyl ketone to this dispersion, the mixture is thoroughly stirred and mixed using a propeller mixer to ensure that the phosphor is uniformly dispersed and that the mixing ratio of the binder and the phosphor is 1:1. 20. A coating liquid with a viscosity of 25 to 35 PS (25°C) was prepared. This coating liquid was uniformly applied to the surface of a support with a conductive coating layer placed horizontally on a glass plate using a doctor blade. After coating, the support on which the coating film was formed was placed in a dryer, and the internal temperature was gradually raised to 25°C or 6100°C to dry the coating film.In this way, the coating film was dried. A stimulable phosphor layer with a layer thickness of 250 μm was formed on the stimulable undercoat layer. Next, a transparent film of polyethylene terephthalate (12 μm thick, a polyester adhesive was applied) on the stimulable phosphor layer. A transparent protective film was formed by placing and adhering the adhesive layer (with the adhesive layer facing down).In this way, the support, the coating layer containing conductive zinc oxide whiskers, and the brightening layer were bonded in this order. A radiation image storage panel composed of an exhaustible phosphor layer and a transparent protective film was manufactured [Figure 1 (
See 2)]. [Comparative Example 1] In Example 1, conductive zinc oxide whiskers were used at 5 nOz
and InO□ to make it conductive.
A radiation irradiation film consisting of a support, a conductive undercoat layer, a stimulable phosphor layer, and a transparent protective film was prepared in the same manner except that the conductive whiskers (Dentor B 200, manufactured by Taikyoku Kagaku ■) were used. An image conversion panel was manufactured. [Comparative Example 2] A sample was prepared in the same manner as in Example 1 except that the conductive zinc oxide whiskers were changed to powdered zinc oxide, but comprised of a support, a conductive undercoat layer, a stimulable phosphor layer, and a transparent protective film. A radiation image conversion panel was manufactured using the following methods. [Example 2] In a dioxane solution of copolyester resin (Pylon 3 Kano, manufactured by Toyobo ■), conductive zinc oxide whiskers (trade name, Panatetra, manufactured by Matsushita Industrial Equipment ■) and powdered BaFBr (
Using a propeller mixer, a coating liquid (B a F B
' r Amount of polyester resin relative to solid content: 20% by weight, amount of conductive whisker relative to BaFBr solid content = 1
0% by weight) was prepared. White polyethylene terephthalate sheet mixed with barium sulfate placed horizontally on a glass plate (support, thickness: 25
0 μm), apply the coating solution marked “-” evenly using a doctor blade to form a coating film.
It was heated to 00° C. and dried to form a conductive light-reflecting layer with a layer thickness of about 40 μm. In the same manner as in Example 1, a stimulable phosphor layer and a transparent protective film were formed on the support provided with the conductive light-reflecting layer described in 2. A radiation image conversion panel was manufactured, which was composed of a conductive light-reflecting layer containing a stimulable phosphor layer, and a transparent protective film [see Fig. 1 (3)].
)reference]. [Comparative Example 3] In Example 2, conductive zinc oxide whiskers were replaced with SnO2
20・nTio which was made conductive by and 1no2
A radiation image was prepared in the same manner except that the conductive whiskers (Dentor BK 200, manufactured by Daikyoku Kagaku ■) in No. 2 were used, but were composed of a support, a conductive light-reflecting layer, an exhaustible phosphor layer, and a transparent protective film. A conversion panel was manufactured. [Comparative Example 4] In the same manner as in Example 2, except that the conductive zinc oxide whiskers were changed to powdered zinc oxide, a support layer, a conductive light-reflecting layer, a stimulable phosphor layer, and transparent protective clothing were prepared in the same manner as in Example 2. A radiation image conversion panel was manufactured. [Example 3] Powdered divalent europium activated barium iodine fluoride bromide phosphor (B a F B ro Q I 0.:0.0
01Eu") 200g, polyurethane (Hinter brand name Tesmolac TP old, -5-2625, solid content 40%,
Add 22.5 g of epoxy resin (anti-yellowing agent, trade name Epicote 1001, manufactured by Yuka Shell Epoxy ■) to a 1=1 mixed solvent of methyl ethyl ketone and 2-propanol. Then, use a propeller mixer to uniformly disperse the coating liquid (viscosity: 3
0PS, 25°C) was prepared. Apply the coating solution described in 1 to 1 of a polyethylene terephthalate sheet (thickness: 180 μm) coated with a silicone mold release agent.
- After forming a uniform coating 1112 using a doctor blade, this coating 1112 was dried by heating to prepare a phosphor sheet. On the surface of a support with a conductive undercoat layer prepared in the same manner as in Example 1, the phosphor sheet described in L was placed and subjected to pressure compression treatment. The pressure compression treatment was performed using a calender roll, at a pressure of 400 kgw/Cml, and at a temperature of 80°C.
It was conducted continuously under the following conditions. By this compression treatment, the phosphor sheet was completely fused to the conductive undercoat layer of the support. Next, a transparent film of polyethylene terephthalate (thickness 210 μm, marked with a polyester adhesive (・J”i-) was placed on top of the phosphor sheet, with the adhesive layer side facing toward C, and bonded. , a transparent protective film was formed. In this way, a radiation image conversion panel was produced, which was composed of a support, an undercoat layer containing conductive zinc oxide whiskers, a stimulable phosphor layer, and a transparent protective film in this order. [Figure 1 (
See 2)]. [Comparative Example 51 In Example 3, conductive zinc oxide whiskers were replaced with SnO2
and InO2 to make it conductive.
The same procedure was used except that a support on which a conductive undercoat layer was formed was used in place of the conductive whiskers (Tyndole IIK 200, manufactured by Otsuka Chemical @) in No. 2. A radiation image conversion panel consisting of a phosphor layer, a transparency film, and an IF film was manufactured. [Comparative Example 6] A conductive undercoat layer was formed by replacing the tetraelectric zinc oxide whiskers with powdered zinc oxide, but a support was used in the same manner as in Example 3. A radiation image storage panel consisting of a coating layer, a stimulable phosphor layer and a transparent protective film was manufactured. [Evaluation Test] Next, each radiation image conversion panel was subjected to the following (1) surface electrical resistance test, (2) conveyance property test, and (3)
Image unevenness generation test, (4) reflectance measurement test, and (5)
)Evaluation was performed by sensitivity/sharpness test (image quality test). (1) Surface electrical resistance test The supports of Examples 1 to 3 and Comparative Examples 1 to 6 each provided with each layer containing a conductive material were
A test piece was prepared by cutting it into a size of 110 mm. A circular electrode (P-601 type, manufactured by Kawaguchi Electric Seisakusho ■) is a must! j
i-1 (EV-40 type super megohmmeter, manufactured by II l'l Denki Seisakusho ■), a test piece was placed on the ``-'' of this circular electrode, pressure was applied to ``1, and the electricity on the surface of the test piece was measured. Resistance (SR) was measured. The measurement was carried out under conditions of a temperature of 23° C., N degree of 53% RH. The results obtained are shown in Table 1. Table 1 Surface electrical resistivity (Ω) Example 1 Comparative example 1 Comparative example 2 Conductive zinc oxide whisker-containing undercoat layer 101O Conductive treatment with 2O-nTi02 Whisker-containing undercoat layer 1010 Containing conductive zinc oxide powder Undercoat layer 1014 or more'' Example 2 Comparative Example 3 Comparative Example 2 Light reflective layer containing conductive zinc oxide whiskers 1012 Light reflective layer containing 20·nTlO2 whiskers for conductive treatment 1012 Light reflective layer containing conductive powder zinc oxide 101' Above Example 3 Conductive zinc oxide whisker-containing undercoat layer 10 Comparative example 5 Conductive treatment with 2O-nTio2 whisker-containing undercoat layer 1oIQ Comparative example 2 Conductive powder zinc oxide-containing undercoat layer 1014 and above 1-Table 1 As is clear from the results shown, all of the layers using conductive zinc oxide whiskers according to the present invention (Examples 1 to 3) had a surface electrical resistivity of 10 12 Ω or more. Also,
Even in the layers using 20·n TiO2 whiskers in the known conductive treatment (Comparative Examples 1. and 5), the surface electrical resistivity was IQ.
It was 12Ω or less. On the other hand, in the layer using the known conductive powder zinc oxide (Comparative Example 2.4.6), the surface electrical resistivity was 10<14 >[Omega] or more. (2) Conveyance Characteristic Test The conveyance characteristic test was carried out using a static testing machine as shown in FIG. In FIG. 2, the static testing machine is
1" and one stage 22 for potential measurement. The transport means 21.21" includes rollers 23a and 23 made of urethane rubber.
b. It consists of an endless heald 24 extended by this roller and an auxiliary roller 25 made of phenolic resin. Further, the potential measuring means 22 includes a detecting section 26, and a voltmeter 27 and a recorder 28 connected to the detecting section. To evaluate the conveyance characteristics, the radiation image conversion panel 29 is fed into the conveyance means 21.
The detection unit 26 is brought into contact with the surface of the protective film (surface of the protective film) and the surface potential (
This was done by measuring KV). The results obtained are shown in Table 2 below. (3) Image unevenness characteristic test The radiation image conversion panel irradiated with X-rays was fed into the static testing machine (installed in a dark room) shown in FIG. Next, the panel was read out using a radiation image reading device (FCCH2 manufactured by Fuji Photo Film), and then imaged on a photographic film. The photographic film was visually observed and evaluated based on the presence or absence of noise (static marks due to discharge). The test was conducted at a temperature of 10°C and a humidity of 2.
The test was carried out under the condition of 0% RH. The results obtained are shown in Table 2. The following margin is the second surface cloth (+7 (V) Noise generation 11 Example 1 Comparative example 1 Comparative example 2 0 , 8 0 , 8 7 , 0 Example 2 Comparative example 3 Comparative example 4 0 , 7 9 , 0 Example 3 -0.8 Non-comparative example 5 -0.8 Non-comparative example 6
As is clear from the results shown in Table 2, row -7.0, in the radiation image storage panels of the present invention (Examples 1 to 3) containing conductive zinc oxide whiskers, the potential on the panel surface remains constant even after transportation. did not change much, no noise was generated, and a good antistatic effect was exhibited. In addition, in the case of known radiation image conversion panels (Comparative Examples 1. and 5) that use 2O-nTiO2 whiskers for conductivity treatment, the potential on the panel surface does not change much even after transportation, and noise occurs. It showed a good antistatic effect. On the other hand, in the known radiation image conversion panel using conductive powder zinc oxide (Comparative Example 2.4.6), the potential difference on the panel surface after transportation was large, and a large amount of noise due to discharge was generated on the photographic film 1-. did. (4) Reflectance measurement test The reflectance at a wavelength of 400 nm of the support on which the conductive undercoat layer or conductive light reflection layer of Examples 1 to 3 and Comparative Examples 1 to 6 is applied was measured using a spectrophotometer (self-recording spectrophotometer). 330, manufactured by Hitachi, Ltd.). The results are shown in Table 3. Table 3 Reflectance (%) Example 1 Comparative Example 1 Comparative Example 2 Coating layer containing conductive zinc oxide whiskers 85 Conductive treatment 1 (2Q-nTiO2 Coating layer containing whiskers) 79 Coating layer containing conductive powder zinc oxide Coating layer 84 Example 2 Comparative Example 3 Comparative Example 2 Light reflective layer containing conductive zinc oxide whiskers 90 Light reflective layer containing 2O-nTiO2 whiskers for conductive treatment 82 Light reflective layer containing conductive powder zinc oxide 90 Example 3 Conductive Comparative Example 5 Undercoat layer containing zinc oxide whiskers Undercoat layer containing 0-nTiO2 whiskers for conductive treatment 79 Comparative Example 2 Undercoat layer containing conductive powder zinc oxide 84 As is clear from the results shown in Table 3. , 2O-
Comparative Example 1: A known support having a layer using nT i 02 whiskers. , 5) have low reflectance. In contrast, supports with layers using conductive zinc oxide whiskers according to the invention (Examples 1 to 3) and supports with layers using known conductive powdered zinc oxide (Comparative Examples 2.4) .6)
showed high reflectance. (5) Sensitivity/Sharpness Test (Image Quality Test) Each radiation image conversion panel (Examples 1 to 3 and Comparative Examples 1 to 6) was evaluated by the sensitivity test and image sharpness test described below. 1) Sensitivity test After irradiating the radiation image conversion panel with X-rays with a tube voltage of 80 KVp, a He-Ne laser beam (wavelength 632.8 n
m), and the amount of luminescence was measured. This relative value of the amount of light emission corresponds to the relative value of sensitivity. 2) Image sharpness test After irradiating the radiation image conversion panel with X-rays with a tube voltage of 80 KVp,
) to excite the phosphor particles, and the stimulated luminescence emitted from the stimulable phosphor layer is received by a light receiver (photomultiplier tube with spectral sensitivity S-5) and converted into an electrical signal. This was reproduced as an image by an image reproducing device to obtain an image on a display device. The modulation transfer function (MTF) of the obtained image was measured and expressed as a value of spatial frequency 2 cycles/mm. The results obtained are shown in graphical form in FIGS. 3, 4, and 5. Each country shows the relationship between the relative luminescence amount in each radiation image conversion panel and the sharpness of the obtained image. From these results, it was found that in the radiation image conversion panel according to the present invention (Examples 1 to 3) and the radiation image conversion panel using a layer using known conductive powder oxidized lead (Comparative Example 2.4.6), For the known radiation image conversion panel using a layer with 2o·nTiO2 whiskers for conductivity treatment, at the same sharpness the relative luminescence (this value corresponds to the sensitivity) is significantly higher, i.e. It can be seen that the sharpness is significantly higher at the same sensitivity.

[Brief explanation of the drawing]

FIGS. 1 (1) to (5) are schematic diagrams showing examples of the configuration of a radiation image conversion panel according to the present invention. FIG. 2 is a schematic diagram showing the configuration of a static tester for evaluating the conveyance characteristics of radiation image conversion panels. It is a graph showing the relationship between the relative luminescence amount and the sharpness of the obtained image. , support, ■ - Stimulable phosphor layer, - Protective film, Coating layer, Light reflecting layer: Adhesive layer, : Back layer

Claims (1)

[Claims] 1. In a radiation image conversion panel having a support made of a plastic film or paper and a stimulable phosphor layer provided thereon, at least a portion of the radiation image conversion panel is electrically conductive. A radiation image conversion panel characterized by containing zinc oxide whiskers. 2. The radiation image storage panel according to claim 1, wherein the support contains a white pigment. 3. The radiation image storage panel has an undercoat layer between the support and the stimulable phosphor layer, the undercoat layer contains conductive zinc oxide whiskers, and the undercoat layer contains conductive zinc oxide whiskers. The radiation image conversion panel according to claim 1, characterized in that the surface electrical resistivity is 10^1^2 Ω or less. 4. The radiation image storage panel has a reflective layer between the support and the stimulable phosphor layer, the reflective layer contains conductive zinc oxide whiskers, and the reflective layer has a surface electrical The radiation image conversion panel according to claim 1, having a resistivity of 10^1^2 Ω or less.